1. Field of the Invention
Tbe present invention relates generally to arming devices for spinning munitions and, more particularly, to novel electromechanical means to regulate the final arming of the fuze of a spinning munition.
2. 2. Background Art.
In U.S. Pat. No. 3,264,995, issued Aug. 9, 1966, to Libby et.al., describes mechanical means for arming a missile and firing it on contact, principally for use with a missile which is rotated in flight. At the heart of the mechanism is an unbalanced slider carrying the primary explosive which arms the missile by moving the primary explosive under the firing pin. Until the missile reaches a predetermined rate of rotation, such movement is prevented by spring-biased weights inserted into the sides of the slider. The slider is further prevented from such movement by the firing pin itself which, until the missile reaches arming rate of rotation, is inserted into and holds the slider in the nonarmed position. The pin is withdrawn from the slider by a centrifugal governor when a predetermined rate of rotation is reached. Thus, arming of the missile takes place at a predetermined desired distance from the point of firing. A spinning inertia ring is provided to cause detonation of the principal explosive charge upon grazing strikes having incident angles as low as 5 degrees.
U.S. Pat. No. 4,869,172, issued Sept. 26, 1989, to Webb, described a safe and arm mechanism for an pxoloding projectile to be fired from a rifled gun. The safe and arm mechanism includes a detonating device and a spin actuated escapement mechanism for delayed arming as well as a setback device normally blocking the escapement mechanism and operable upon a concurrence of axial acceleration, angular acceleration, and angular velocity above predetermined thresholds to free the escapement mechanism. A command arming arrangement normally precludes movement of the escapement mechanism into a fully armed condition and is operable upon command to free the escapement mechanism to move to the fully armed position. A void sensing mechanism for sensing deceleration caused by the projectile striking a target followed by a significant reduction of the deceleration then enables the detonating device.
The disclosures of both the above patents are hereby made a part hereof by reference.
The types of arming devices described in the above patents, as well as other commonly employed devices, are well known and provide reliable arming at 400 to 800 calibers from the gun muzzle. However, they do not provide a command arming feature to allow predetermined arming near the target area--well beyond the 800 caliber arming distance. Also, newer weapon systems and tactical methods will require greater control of the arming event to preclude the detonation of the warhead by electronic countermeasures. Such detonation can have severe consequences if it occurs in proximity to friendly forces. Thus, the armed forces have a need for a fuze that will give the required 400 to 800 calibers safe arming distance beyond the muzzle and extended arming distance to protect friendly forces and prevent detonation by electronic countermeasures.
Accordingly, it is a principal object of the present invention to provide a safe and arm device for spinning munitions, which device can provide safe arming of the munitions beyond 400 to 800 calibers from the gun muzzle.
It is an additional object of the invention to provide such a device that can prevent detonation by electronic countermeasures of the warhead on which the device is mounted.
it is a further object of the invention to provide such a device that is simple and highly reliable.
Other objects of the present invention, as well as particular features and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.